Study on reasonable size of protective coal pillars in roadway of rock burst coal seam

He Qi; Zhou Yu; Zhong Taoping; Li Zhenlei

doi:10.19896/j.cnki.mtkj.2025.03.009

Abstract：Determining the appropriate size of the protective coal pillar for the main roadway is crucial for the long-term stability of the coal seam's main tunnel.Taking the main roadway of rock burst coal seam in a mine as the research object,the stress distribution of the surrounding rock of central main roadway under the condition of different widths of protective coal pillars reserved in the first working face and the continuous working face was studied by using the methods of numerical simulation and engineering analogy.The results show that when the width of the protective coal pillar is 400～100 m,the boundary stress of main roadway increases by 1.28%-11.25%due to the first mining face,and the significant increase of the boundary stress of main roadway occurs when the width of the coal pillar is less than 250 m.When the width of the protective coal pillar is fixed,the more the number of continuous working faces,the greater the stress of the surrounding rock of central roadway,the stress of the roadway boundary increases by 77.99%compared with the first min-ing face.The practice in similar mines has proved that when the width of protective coal pillar of main roadway is less than 250 m,it is not conducive to the stability of main roadway in the later stage and increases the risk of rock burst.Based on comprehensive considera-tion,it is determined that the reasonable size of main roadway protection coal pillar in the mine is not less than 250 m.